I am far from a legal expert, but if the Supreme Court rules against Illinois in these main cases would or could the rulings leave it open for localities and municipalities to ban people from conceal carrying? If so I would imagine it is not a stretch that we will see Chicago ban or somehow severely restrict it.

I doubt Chicago would be able to get away with that. SCOTUS already found in McDonald that 2A was incorporated against both states and localities through the Due Process Clause of 14A. Assuming that SCOTUS rules that a ban on carry is a violation of 2A, that would also be incorporated under McDonald.